Due to rapid development of Internet technologies and high-throughput and low-cost features of a wireless local area network (WLAN), the WLAN technology based on the IEEE 802.11 standard is widely used. However, growing congestion of a WLAN frequency band is caused due to limited spectrum resources of the WLAN. Moreover, an unlicensed frequency band is used in the WLAN. Therefore, quality of service cannot be guaranteed in the aspect of spectrum use for the WLAN.
To improve spectral usage efficiency of the WLAN, in the prior art, multiple access points (Access Point, AP) may be used to perform downlink coordinated processing. For example, by means of a precoding technology, multiple APs may send, in a same time-frequency resource by using a beamforming matrix, data to stations (STA) corresponding respectively to the APs. However, in uplink coordinated processing, after multiple stations establish an uplink coordinated relationship, and after one station obtains a right to use a channel, stations that coordinate with the station cannot synchronously learn that the station has obtained the right to use a channel, and cannot obtain in time a beamforming matrix for coordinated transmission, so that uplink coordinated transmission cannot be performed. Therefore, the prior art cannot support multiple stations to send, in a same time-frequency resource by using a beamforming matrix, data to APs corresponding respectively to the stations, resulting in low spectral usage efficiency.